Water-heating unit



April 22, 1952 PETERS 2,594,067

WATER HEATING UNIT Filed Feb. 11, 1949 2 SHEETS-SHEET 1 April 22, 1952 H. w. PETERS WATER-HEATING UNIT 2 SHEETS-SHEET 2 Filed Feb. 11, 1949 \Nu QRU Patented Apr. 22, 1952 Herbert W; Peters, Milwaukee; Wis., assignor to Gory Corporation, Chicago, 11]., a corporation of Delaware Application February 11, 1949, Serial Ne. 75,818 4 Claims. (01. 122-236) 1 The present invention is directed to ages-fired water heating unit of small dimensions which may be used for various purposes such as to preheat the water supply to a primary apparatusa commercial coffee brewer, for example. An illustrative embodiment of invention is shown in the accompanying drawings, wherein:

Figure 1 is a plan view, partly in section, showing the principal elements of the water heating unit as well as the water conduits leading thereto and therefrom;

Fig. 2 is a vertical sectional view taken at line 2-2 of Fig. 1; and

Figs. 3 and 4 are similar views taken respectively at lines 3-3 and 4-4 of Fig. 2.

The present water heating unit I 2 comprises a generally rectangular sheet metal housing 35 within which is mounted water heating and control equipment including a rectangular tank 36 provided along the external top and side surfaces with thermal insulation 31 held in place by an outer sheet metal shell 38.

The ends of the tank 35 are defined by front and rear header plates 40 and 4| the former of which is of extensive area, as best shown in Fig. 3, and constitutes an integral part of a hood 42 which further includes a rearwardly extending plate 43 having top and side portions. The hood 42 extends to a vent opening 45 in the top of the housing 35 and serves to conduct the products of combustion to said opening.

Cold water is supplied to the water heating unit l2 through the medium of a pipe 44 which is connected through a T fitting 46 to a pair of oppositely extending branch pipes 41 and 48, each connected to one end, individually, of a pair of fuel economizers 49, 49. The discharge ends of the economizers communicate with a distribution pipe to which, in turn, are connected a pair of laterally spaced parallel injection tubes 52 and 53 which extend inwardly of the tank 36 and are perforated throughout their lengths, interiorly of said tank.

The fuel economizers 49, 49 each comprise a pipe 55, of considerably larger bore than that of the pipes connecting to the two ends thereof; and each of said pipes 55 is equipped with numerous radially projecting sheet metal fins 56 spaced lengthwise therealong. The two ends of each of the two pipes 55 are provided with screw caps 51 threaded to accommodate fittings for the connecting pipe 41, 48 and 5|. Each of said economizers is positioned underneath the hood 42 and directly in the path of the hot products of combustion. They consequently serve to salvage a substantial part of the heat which otherwise would be dissipated wastefully, and to corn duct the same into the water heating tank 35.

Underneath and somewhat below the tank 35 is an elongate tubular gas burner 58, which cit tends lengthwise of said tank and is provided with numerous jet orifices 59 through which the gaseous fuel emerges. These orifices 59 are iscated along the top surface of the burner 58 so that gas emerging from the burner will at once proceed upwardly.

Gas is supplied to the burner 58 through-apipe 50 in which are inserted a pressure regulating valve 6|, a pilot safety valve s2 and a thermostatically controlled valve 63. The function of the valve Si is, of course, to ensure uniform gas pressure at the burner. The function of the pilot safety valve 52 is to shut ofi the gas in event of the pilot light becoming extinct. This is con-- nected in circuit with a thermocouple associated with the pilot burner 64 and subjected to the pilot flame. The valve 63 functions to turn'on the gas to the main burner 58 whenever the temperature of the water in the tank 36 falls beleitif a certain predetermined value, and to turn on the gas when the water temperature has reached a predetermined higher value.

The pilot burner 64 is supplied with gas through a tube 55 the intake end of which is connected into the body of the valve 63 at the intake side thereof, so that the supply of gas to the pilot is not affected by the opening and closing movements of the valve 63.

Two strips of refractory material 59, 69 are lo= cated below and extend lengthwise of the water heating tank 36. These are supported on channels 10 which, in turn, are secured at their ends to the header plates it and 4!; and said strips, together with their supports 18, are spaced apartlaterally and narrowly spaced from the bottom of the tank 36, as most clearly shown in Fig. 4. The flame from the burner 58 rises vertically therefrom, and the hot products of combustion divide and pass through the narrow spaces H, H and thence upwardly under the hood 42 and therealong to the vent 45. The strips 69 serve to effect a maximum concentration of hot gases along the bottom plate of the tank 36, thus achieving a very high rate of heat transfer by conduction; and at the same time said strips function as radiators and transmit through radiation to the tank 36 a large part of the heat which might otherwise be lost as a result of conduction in the wrong direction.

A thermostat 66 connected to the rear header 4| of the tank 36 extends therein near the bottom thereof and is, accordingly, responsive to the temperature of the water near the bottom of the tank. This thermostat is connected in circuit with the magnet winding of the valve 63 for the control thereof. The insulation 31 at the top and sides of tank 36 serves to isolate the water within the upper portion of said tank from the heat of the ambient flue gases, thus obviating the possibility of the temperature of the water in the upper portion of the tank being elevated above that in its lower region where the thermostat 66 is directly immersed.

The discharge from the tank 36 is eifected through a pipe 21 in connection with an elbow fitting 61 which extends into the top of the tank 36 and is fixedly secured thereto (see Fig. 2).

The water heating unit l2 preferably is provided with tubular legs 68 which serve to elevate the housing 36 above the surface of the underlying supporting structure and at the same time admit a free flow of air to the main and pilot burners.

It will be seen that the present invention provides a highly eificient auxiliary water heating unit which is admirably adapted to the specific purpose for which it is intended and which,

further, is inexpensive to produce, easy to install, and of such small over-all dimensions as to present the least possible objection grounded on space requirements.

I claim:

lQA water-heating unit comprising a horizontal water-heating tank, a pair of fuel economizers located at either side of said tank, conduits leading from said economizers to said tank, cold water pipe connections leading into said economizers, a hood overlying said tank and economizers, a gas burner disposed below said tank and extending lengthwise thereof, and a pair of refractory strips located below said tank in closely spaced relation to the bottom thereof, said strips extending lengthwise of said tank and spaced apart laterally to form an opening therebetween directly above said gas burner, the arrangement being such that the products of combustion from said burner pass upwardly through said opening and then divide and pass through the narrow spaces between said strips and the bottom of said tank and thence upwardly-past said economizers.

2. A water-heating unit in accordance with claim 1 wherein said economizers are each substantially co-extensive in length with said tank and said gas burner, and wherein each said cconomizer is provided with radial fins between which pass the hot products of combustion.

3. A water-heating unit according to claim 1 including a thermostat responsive to the temperature of the water in said tank and operative to control the flow of gas to said burner whereby to maintain the water in said tank within a predetermined narrow temperature range.

4. A water-heating unit comprising a horizontal water-heating tank, a water-injection tube extending into said tank, a hood overlying said tank, a pair of fuel economizers located at either side of said tank and each connected at one end to said water-injection tube, the other ends of said economizers being adapted for connection to a cold water supply, said economizers being situated beneath said hood, a gas burner disposed below said tank and extending lengthwise thereof, said burner being so situated that the products of combustion therefrom contact the bottom of said tank and then proceed upwardly past said economizers underneath said hood, thermal, insulation covering the sides and top of said tank underneath said hood and effective to insulate the water in the upper portion of said tank from the ambient hot flue gases, a control valve for said gas burner, and thermoresponsive means subject to the temperature ofthe water in said tank for controlling said control valve in a manner eifective to maintain the water temperature within a predetermined narrow range, said water injection tube and thermoresponsive means being located near the bottom of said tank, the arrangement being'such that said thermo-responsive means is promptly affected by the temperature reduction of the water in the bottom of said tank incident to the draw-' ing off of hot water from said tank and the accompanying introduction of cold water.

HERBERT W. PETERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Alexander May 4, 1948 

